Climate change is transforming the nature of global water insecurity. While the threat posed by rising temperatures is now firmly established on the international agenda, insufficient attention has been paid to the implications for vulnerable agricultural producers in developing countries.
Global warming will transform the hydrological patterns that determine the availability of water. Modeling exercises point to complex outcomes that will be shaped by micro-climates. But the overwhelming weight of evidence can be summarized in a simple formulation: many of the world’s most water-stressed areas will get less water, and water flows will become less predictable and more subject to extreme events. Among the projected outcomes:
(1) Marked reductions in water availability in East Africa, the Sahel and Southern Africa as rainfall declines and temperature rises, with large productivity losses in basic food staples. Projections for rain fed areas in East Africa point to potential productivity losses of up to 33% in maize and more than 20% for sorghum and 18% for millet.
(2) The disruption of food production systems exposing an additional 75-125 million people to the threat of hunger.
(3) Accelerated glacial melt, leading to medium term reductions in water availability across a large group of countries in East Asia, Latin America and South Asia.
(4) Disruption to monsoon patterns in South Asia, with the potential for more rain but also fewer rainy days and more people affected by drought.
(5) Rising sea levels resulting in freshwater losses in river delta systems in countries such as Bangladesh, Egypt and Thailand.
The international response to the water security threat posed by climate change has been inadequate. Multilateral efforts have focused on mitigating future climate change. These efforts are critical. Restricting future global warming to an increase of no more than 2 degrees Celsius over pre-industrial levels should be a priority. Attaining that target will require major adjustments in the energy policies of both the industrial and developing countries, supported by financing for the transfer of clean technologies.
The crisis in water and sanitation is, above all, a crisis for the poor. Almost 2 in 3 people lacking access to clean water survive on less than $2 a day, with 1 in 3 living on less than $1 a day. More than 660 million people without sanitation live on less than $2 a day, and more than 385 million on less than $1 a day.
These facts have important public policy implications. They point clearly towards the limited capacity of un-served populations to finance improved access through private spending. While the private sector may have a role to play in delivery, public financing holds the key to overcoming deficits in water and sanitation.
The distribution of access to adequate water and sanitation in many countries mirrors the distribution of wealth. Access to piped water into the household averages about 85% for the wealthiest 20% of the population, compared with 25% for the poorest 20%. Inequality extends beyond access. The perverse principle that applies across much of the developing world is that the poorest people not only get access to less water, and to less clean water, but they also pay some of the world’s highest prices:
â— People living in the slums of Jakarta, Indonesia; Manila, Philippines; and Nairobi, Kenya, pay 5 – 10 times more for water per unit than those in high-income areas of their own cities and more than consumers pay in London or New York.
â— High-income households use far more water than poor households. In Dares Salam, Tanzania, and Mumbai, India, per capita water use is 15 times higher in high-income suburbs linked to the utility than in slum areas.
â— Inequitable water pricing has perverse consequences for household poverty. The poorest 20% of households in El Salvador, Jamaica and Nicaragua spend on average more than 10% of their household income on water. In the United Kingdom a 3% threshold is seen as an indicator of hardship.